What is the value of this expression when d=3

Answer this question only if you know the answer! 30 points and

The american academy of pediatrics wants to conduct a survey of recently graduated family practitioners to assess why they did not choose pediatrics for their specialization. provide a definition of the population, suggest a sampling frame, and indicate the appropriate sampling unit.

Identify the expression equivalent to 4(x + x + 7) − 2x + 8 − 4 by substituting x = 1 and x = 2.